This invention relates to an Fe-based nano-crystalline alloy and a forming method thereof, wherein the Fe-based nano-crystalline alloy is suitable for use in a transformer, an inductor, a magnetic core included in a motor, or the like.
Use of nonmetallic elements such as Nb for obtaining a nano-crystalline alloy causes a problem that saturation magnetic flux density of the nano-crystalline alloy is lowered. Increase of Fe content and decrease of nonmetallic elements such as Nb ca provide increased saturation magnetic flux density of the nano-crystalline alloy but causes another problem that crystalline particles becomes rough. JP-A 2007-270271 discloses an Fe-based nano-crystalline alloy which can solve the above-mentioned problems.
However, the Fe-based nano-crystalline alloy of JP-A 2007-270271 has large magnetostriction of 14×10−6 and low magnetic permeability. In addition, because large amount of crystal is crystallized while being rapidly cooled, the Fe-based nano-crystalline alloy of JP-A 2007-270271 has poor toughness.